Ubbink OFT/1F Flat Roof Vent/Terminal

The OFT/1F is designed for flat roofs, and we can’t confirm that its aluminium collar is intended to be angled by hand. A small adjustment may be possible, but avoid forcing it or creating creases or damage that could affect the weatherproofing. The vent should remain as close to vertical as possible, with particular care taken to seal the flange correctly to the felt. For a definitive recommendation for an 8–10° pitch, please check with the supplier or our technical team.

The Ubbink OFT/1F Flat Roof Vent/Terminal is designed specifically for flat roofs, so it may not be suitable for your low pitch roof of 15 degrees. However, this can also depend on other factors like the specific installation and roof materials. It would be best to consult with a professional installer or our technical team for the most accurate recommendation based on your specific circumstances.

Yes, you can raise the Ubbink OFT/1F Flat Roof Vent/Terminal - 110mm on your flat grass roof. This is generally done by raising the pipework below the vent or using a purpose-designed extension piece, rather than extending the vent terminal itself. Please ensure that any modifications maintain the integrity of the vent's functionality and comply with any relevant building regulations. If you need more specific advice on how to achieve this, we recommend consulting with a roofing specialist or a professional installer. 

While the Ubbink OFT/1F Flat Roof Vent/Terminal - 110mm is designed to provide effective ventilation, it might not be the best fit for your needs. This is because the pipe diameter of this vent is 110mm, which is smaller than the 150mm requirement of your cooker extractor fan. Even with a reducer, it could potentially compromise the efficiency of the fan due to the smaller vent size. However, there is a larger version of this vent, the Ubbink OFT/1F Flat Roof Vent/Terminal - 160mm, which might be a better match for your cooker extractor fan. This vent has a pipe diameter of 160mm, closer to your requirement. You can view the Ubbink OFT/1F Flat Roof Vent/Terminal - 160mm on our website by clicking here. Before making a decision, I recommend consulting with a professional installer to ensure the vent will work effectively with your extractor fan and meet any building regulations.

To ensure the Ubbink OFT/1F Flat Roof Vent/Terminal is waterproof on your EPDM flat roof, it's crucial that the vent is properly flashed. However, the specific flashing or "witches hat" you need depends on your specific roof setup and the vent product specifications. For this Ubbink OFT/1F Flat Roof Vent/Terminal, it's designed to be compatible with standard roofing materials, so a standard flashing that can accommodate a 110mm pipe should work. However, it's always best to consult with a roofing professional or contractor who is familiar with your specific roofing setup to ensure you get the appropriate flashing.

Yes — your rubber “witches‑hat” EPDM flange does get bonded over the metal flange on the Ubbink OFT‑1F.  

The metal flange on the 110 mm model is 330 mm in diameter, so your EPDM boot must comfortably cover at least that area

100%

You would need to ensure that the felt/bitumen is covering the flange of the vent and that it is fully watertight. 

Yes you can

I will email you the correct one

The Ubbink OFT/1 range is available in five different flange types for different roof coverings, Asphalt, Felt, EPDM, Bitumen and PVC - you just need to state what one you need in the notes

Yes this can be used on a GRP Roof

Yes you can cut the lower pipe to suit your needs

100% yes

Yes 100%

Yes it can 

Please call in and speak with one of the team as there may be alternative ideas 

This item is provided with a flangle suitable for insyallation with Bitumen Felt.

Part of installation will be dressing GRP back over the flange to make this waterproof. We would recommend getting a Roofer to do this job as GRP is a more specialist product.